Memcpy procedure for 80188 embedded system

I need to write a "memcpy" procedure in assembly for an embedded system running on an 80188 microprocessor. Memcpy() copies n bytes from memory area s2 to s1 and returns s1. It is called in C code as follows:

void *memcpy(void *s1, const void *s2, size_t n)

I am very new to assembly programming and is hoping for some advice how this can be done. Btw, is there a compiler which translate C code into assembly?